One thing bothers me though. Why use 1926 as a starting point? Surely most of the "gain" would have occurred since 1970? Using 1970 would certainly put it into a more modern context, considering that the article discusses the fuel economy of jet engines...

I would also be somewhat interested to know how central tendency has changed. Observationally I would guess that it has decreased significantly which means that the situation is afr worse than simply indicating the an average or a median value does.

vander wrote:BMI is utterly useless just saying. I know plenty of people with six packs and BMIs in the 30s.

I would say for guys it is more fashionable to be muscly now as opposed to ever 30 or 40 years ago.

It is primarily a tool to be applied to populations rather than individuals despite the new-age application of it to personal health.

It is certainly not useless, it is just not perfect.

As a cautionary tale on stats however. A few years back the US media and other narrowly informed commentators decried an alarming increase in obesity rates in the US. They had noted an alarming increase in the number of people reported as being obese in a fairly short time. What they failed to understand is that the US had recently adopted a new benchmark for obesity, moving the target from 28% (from memory) to 25 in line with other countries. There are lies, damned lies and statistics.

I have to question the use of BMI even as a population tool. To apply it to an individual is laughable in the extreme. According to my BMI my doctor told me I should be 85kg. My response to him was that's very nice doctor...can you please tell me what happens when I turn 11.

I was so curious as to why this was so far out I researched into where it came from and discovered it was derived in Belgium before my country of birth was discovered. Logically this leads to a thought process with the logical conclusion of how could something invented in Europe where the winters are harsh and the population largely lived on turnips apply to a modern country where foods are varied and plentiful and winters comparatively mild (meaning we are more active etc).

For the same reason comparing 1926 to 2008 is verging on ridiculous. There was a depression on, people were unemployed and many missed meals etc. So what has that got to do with 2008?

BMI is only used because it is easy to do that is it. It tells you little information at all. Any person in any health profession that knows anything knows this. Seriously a tape measure around the waste is much better.

How much of these increases are fat versus muscle bulk? The average is no longer slim 59 and 72kg couples.

Doesnt surprise me. I was speaking to my uncle on the weekend about just this topic, he is 84. He was saying a lot more people rode bikes, walked et etc. Nowdays people will drive almost anywhere no matter the distance. Plus eating habits have changed a lot. How many families nowdays sit together for a meal at dinner, I dont know the stats but I would say half of what used to.

TV also would play a huge role too, look at how many ads there are on that damn box about food, usually crap too.

BMI is what it is, usually if you are overweight, no real point doing a BMI test, as you already know your overweight lol, thats my theory anyways. Bodybuilders are usually in the 30s, i'd say most Rugby players too.

If you can't explain it simply, then you don't understand it well enough.

vander wrote:BMI is only used because it is easy to do that is it. It tells you little information at all. Any person in any health profession that knows anything knows this. Seriously a tape measure around the waste is much better.

rkelsen wrote:If it wasn't relevant or applicable to the majority of the population, then why would doctors continue to use it?

The clinical angle to note is that, hunky body builders and rugby players aren't associated with longevity. When they stop their routine in age, that bulk starts to turn into fat. In due course, they'll be in health troubles. For doctors, health objective for their patients is to be physiologically "fit enough", not to be a gold medal winner within the population.

dynamictiger wrote:For the same reason comparing 1926 to 2008 is verging on ridiculous. There was a depression on, people were unemployed and many missed meals etc. So what has that got to do with 2008?

Actually, 1926 was a boom time. The Great Depression started in 1929. Comparing 1926 to 2008 may end up being reasonably accurate given another couple of decades to look back on it.

dynamictiger wrote:According to my BMI my doctor told me I should be 85kg.

And you're questioning your doctor? There's a reason he/she has that title, you know.

BMI isn't perfect, but the simple fact is that it works for 80% of the population. If you're not an athlete, then you should probably count yourself in that 80%.

If it wasn't relevant or applicable to the majority of the population, then why would doctors continue to use it?

Not at all. BMI is quite bad at detecting a level of health of a person. Even calipers arent very good as they measure subcutaneous fat which is only loosely linked to health problems. Visceral fat is the true indicator of future health problems and often subcutaneous and visceral fat levels are very different. This is where a tape measure can actually be quite handy especially if used with calipers. If my doctor baised everything on BMI I would be finding a new doctor. Doctors arent infallible and from what I hear from people doing medicine is they actually dont get enough training in a lot of things and exercise and nutrition are one of those things they just get the bare minimum in.

vander wrote:Not at all. BMI is quite bad at detecting a level of health of a person. Even calipers arent very good as they measure subcutaneous fat which is only loosely linked to health problems. Visceral fat is the true indicator of future health problems and often subcutaneous and visceral fat levels are very different. This is where a tape measure can actually be quite handy especially if used with calipers. If my doctor baised everything on BMI I would be finding a new doctor. Doctors arent infallible and from what I hear from people doing medicine is they actually dont get enough training in a lot of things and exercise and nutrition are one of those things they just get the bare minimum in.

While this is all true, am I more likely to have more or less visceral fat if I lose weight and therefore have a lower BMI?

If doctors struggle to measure visceral fat, how can I really do this at home? Even a dumbo like me can measure my height and weight and notice if I am out of breath I get walking or cycling and/or that I have a muffin top. I can do this everyday without needing an appointment. Sure, it is not as good as having a group of trained professionals on call, but I do not have that luxury. In summary, BMI is better than nothing as a pie gauge guestimator, I'd argue it is the best easy tool I have.

dynamictiger wrote:I have to question the use of BMI even as a population tool. To apply it to an individual is laughable in the extreme. According to my BMI my doctor told me I should be 85kg. My response to him was that's very nice doctor...can you please tell me what happens when I turn 11.

Clinicians often find pateints rejecting their suggestion that they are overweight - and offeringall sorts of reasons why their BMI isn't to be relied upon.

If BMI is so laughable, please share with us what you think is credible. Later you suggest...

dynamictiger wrote:I am built more like a rugby player or body builder than an overweight person. I was taller than my parents and heavier in primary school.

So what is a credible method of measuring that you are built like a rugby player or body builder ? How is a clinician going to measure that you were taller and heavier than your parents in primary school ? BMI accounts for both terms quite well, but maybe you've got somethingbetter and less easily denied by those who are difficult to persuade.

There is a strong correlation between the population statistics showing that average weights are increasing and the rising rates of diabetes, coronary disease etc.,. So there's every reasonto acknowledge it, and seek to address why we are getting overweight before the health systemcollapses under the burden of treating too many of its consequences.

Cheers

WombatK

Somebody has to do something, and it's just incredibly pathetic that it has to be us -Jerry Garcia

Actually BMI measure is good at what it is intended to do. It is to determine if you are overweight or underweight in relation to your height. Even if you are muscle and have a low body fat % if you are overweight to your height then the BMI measure will let you know this.

wombatK wrote:Clinicians often find pateints rejecting their suggestion that they are overweight - and offeringall sorts of reasons why their BMI isn't to be relied upon.

+1 on this.

As soon as someone mentions BMI, there are heaps of people who find individual examples as to why it doesn't work. If you are a body builder, or a rugby prop, then chances are you know a lot more about your body condition than most people. Most people who don't like BMI are those who ought to pay more attention to it. Sure it isn't 100%, and sure there are exceptions, but it is a good general rule and does apply to most people.

For what it's worth, I'm 184cm and 87kg, so BMI says I'm overweight. I don't like it, and I am and always have been a more solid build than others, but losing 3kg puts me in the normal range, and that's one of my goals (that keeps slipping ).

Actually just had a thought. Farmers, et al. have spent the last however long trying to come up with ways of growing food (animals and crops) bigger and faster than before, and have succeeded admirably. Why are we now so surprised that it is having the same effect on people?

and chemists have spent the last 20 years making poor quality food look good and taste addictiveand marketers have spent the last 20 years convincing us that if we eat this junk food we will be cool, attractive and sucessful